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Jan- 1, C. F. KETTERING BATTERY CHARGING SYSTEM Filed Feb. 11. 191BDynamo J'ngine Dynamo hglne 4% Z esses Patented Jan. 1, 1924.

UNITED STATES CHARLES F. KETTERING, OF DAYTON, OHIO. ASSIGNOR, BY MESNEASSIGNMENTS, TO

DELCO-LIGHT COMPANY, OF DAYTON, OHIO, A CORPORATION OF DELAWAREBATTERY-CHARGING SYSTEM.

Application filed February 11, 1918.

To all whom it may concern:

Be it known that I, CHARLES F. Kn'rrnn me, a citizen of the UnitedStates of America, residing at Dayton, county of Montgomery, and Stateof Ohio, have in vented certain new and useful Improve Another object ofthisjnventionf is to provideyan electrolyte-controlled relay in whichthe normal action of the relay is modified or prevented according totheconditionof the electrolyte of the storage battery.

Another object of this invention is to pro vide a displacement member-inthe electro- Iyte'of-the storage-battery for controlling the' relay,-which is self-compensating. for the .increase in specific-gravity of theelec trolyte duetotbe evaporation, with the re- 1 Suit that the lifting.iorce exerted by=the electrolyteuupon 'the displacement memberremainsithe same;

Other and further objects erence being had. to the accompanying drawin 1nthe drawings: Y a

Fig. 1 'is a wiring diagram showing a bat- Itery charging circuitincluding an 8mbOdI- mentof the engine stopping device included in thepresent invention; and I Fig. 2 is a wiring diagram of a batterycharging system similar to that shown in Fig. 1; 'but including amodified form of the invention.

Referring to Fig. 1, 20 designates an en-' gine-generator set supplyingcurrent through wires 21 and-22 forcharging: storage batteries 23,.= 24and 25. connected therewith.

The charging current passes through'22 and 26, across contacts 27. ofcircuit breaker28, along armature 29, through magnet "Winding'30,through conducto'r3l, through .bat-

-=teries 23, 24 and 25, and through conductor ofthe present inventionwill be apparent from the follow' ing description of embodiinentsthereof, ref- Serial No. 216,466.

32 and 21 to the generator. The ignition circuit comprises conductor 33connected to armature 29 of circuit breaker 28, switch contact members35 and 36 of the ignition switch 34, conductor 37, ignition timer 38,wire 39, ignition coil 40, and wire 41 to con ductor 21. The coil isconnected by means of wire 42 to the spark plug 43 on the engine.

The electromagnet winding 44 of cutout relay 45 is connected across thecharging circuitas shown. The relay magnet core 46 is mounted on a frame47 which supports for movement toward the core 46, the armature 48,which is normally held away from the core by means of balancingspring49, and a displacement member 50 which is suspended in the electrolyteof the storage cell 25 by means of member 51 connected at one end ofarmature 48. The upper level of said electrolyte isindicatedbythe-numeral BOI The other end of armature 48 is provided with a member52tdesigned to engage con-' tact member 36 of ignition switch 34 and tocause the opening of the" ignition circuit when said armature isattracted by the magnet of relay 45. xi

The operation of the charging system is as followsz 1.

By depressing armature-29 contacts 27 will close permitting current fromthe bat tery to flow throughconductors 32 and '21 to generator 20 andback'throu'gh conductors 22 and 26, across contact 27'through armature29, magnet winding 30, and conductor 31. The current from the batterywill cause the generator to operate. asa motor and ellect the startinhof the=engine. As soon as the engine has become self actuating, current will flow from generator to the battery through the chargingcircuit already described. The circuit breaker magnet being energized bycurrent carried throu h winding'30, the armature 29 will be he d in attracted position and the contact 27 will remain closed. When thebatteriesare fully charged the voltage in the charging circuit will riseto such an extent as to energize the magnet of relay 45 sufficiently. toattract armature 48, and therebyto effect breaking of the ignitioncircuit, thereby causing the stopping of the engine. Then the circuitbreaker contacts 27 will tend to disconnect the generator from thebattery.

In order to permit the operation of the engine in a case where thebatteries are fully discharged and sulphated, it would be necessary toprovide some means of, preventing the operation of the cutout relay forthe ignition circuit, for the reason that when the batteries are in thecondition mentioned, the voltage of the charging circuit would rise tosuch an extent that the relay would operate to open the ignitioncircuit. This rise in voltage may'be due to the state of resistance ofthe' battery when in a fully dis- 7 charged and siilphatcd condition. Inorder to overcome this difficulty I take advantage of the fact that thespecific gravity of the electrolyte of the storage batteries is muchlower when the'batrcrics re discharged and sulphated. Therefore, sincethe lifting force exerted upon the displacement meni ber by theelectrolyte ol the cell '25 in the condition mentioned, has beendiminished, the force due to gravity exerted by member 50 upon armatureis will be correspondingly increased, with the result that the magnet ofrelay 45 will be ineffective to= attractiirma ture 48 sufficiently tocause the opening of the; ignition circuit.

1 Fig.2 shows diagrammatically a modified form. of the inventiondescribed, in. which the; charging circuit and the ignition circuitare'the same-as in the form of the invention shown: in Fig. 1; i In;Fig; 2, however, the

voltagerelay ClTClLlll across the (Zhill'glng- Cl1';.

cuit comprises, inadditionto magnet winding 44:, a switch-60, comprisingcontact mernbers,61: and 62.. Contact member 61 is de-v signed :tobemovable with respect to member 62, under the influence of her50isuspended .in the electrolyte: of cell'25 by means of member 51attached to thef-ree end ofiswitch membenfil- When carryingacu'rrent-ofsuflicient magnitude, that is, when'zthe number oampereturns of magnet lee-has been sufiicientlyi increased,then ma-g- 7net. core 4L6. will be energized sulliciently to causethe attraction ofarmature 48 against .thenactiori ofcbalancingspring 49; andthereby:efiiectseparation. of contact members 35-amlz-36 of ignitionswitch 345. The open ntion of the modified form of the inventionshowinin: Fig. :2 iszis follows:

-Whe'n, the batteries are discharged. and snlphated the specific gravityof the electroly'te will be lo\v,and the displacement member 50relatively heavy, with the result that the switch 60. will be openTherefore, although the voltage of the charging circuit would. besufiicientto; cause the attraction of thearma-ture iS of relay if), andthe consequent opening of ignition switch i-t. the said; relay fi'cannot operate since switch in the relay circuit is open. Since theignition circuit remains closed, the engine will continue tooperate.During the first stages of battery charging,- the resistance due to thesulphated condition of the batteries is broken down and there is acorresponding displacement memdecrease in the voltage oi the chargingcircuit. From this point, oin the voltage 'riscs gradually according tothe condition of battery charge, as is well understood in theart l'Vhenthe batteries have'beenj charged to a To certain degree an thespecifivgravity of the electrolyte has reached a certain point, thedisplacement member 50 will have risen to such a certain extent as topermit the closing of switch members 61 and 62. The closing of switch 60will permit a small amount of current to flow through the relay magnetwinding 44. As soon as the batteries have become charged the voltage ofthe charging circuit will rise to such a value as will cause the relayto operate andopeu the ignition system, and thereby cause the stoppingof the engine.

From the foregoing description it willbe. apparent that there has beenprovided in both of the embodimentsoi my invention, means for effectingthe stopping of the engine which is dependent botl1- on the voltageofthe chargingcircuit; and) on. the-condition, of the electrolyteinithersboragei battery.. 0 There is a time 'when; thelnbntteryzisdischarged and snlphated, and the voltage; of the charging. circuit issutficienttaoperatma relay causing the stopping ofi theengixm; SIt is?the function. of the :displacementi member to prevent theoperation ofthezrelayrbyivirr tee of the decreased buoyancy of bheelem trolyte.W'hen atthe: otherextiremfl of bat? tery conditiong-thateisl;whenz-ithe-xbeltteries are fully charged, anditriszdesiredi :to;sto.pv100. the engine, thelvoltagebirths. charging cir cuit isagain-.sufiiciently 'great.to operate-a1 voltage 1 relay to efl ect Ethestopping ;ofi the engine; The displacement member. 159 will now beinoperative tomofli fiyithki fiunctiomofid the voltage-relay, since thesgrnvityi of the electrolyte has risen wi-tln-t e'iresuzlt that thedisplacement emember'is"buoyedsup to a point where it can no longer.preventzthe'. operation of the rclay;

It will beenotednthat the .=.displacemerit member 50 is provided with atapered upperend, and is suspended with the upper endlbcated near thenormalilevcl. 80:0f Eheelt trolyte. Thista'per is so proportioned-thatas evaporation of theelectrolyte takesaplaceand increasing portions-ofthe displacement-- member extend above the; level of the electrolyte,the quantity of eleetrolyte'displaced will be decreased inPI'OPOlTtiODJlOi the in-'-5120 crease in specific gravity. Thusthe-lifting force exerted upon the displacement 'mei'nber will-remainconstant; i I Y While the electrolytecontrolled relay. is I describedand shownintwo modified -forrns as applied to a batterychargingsystem;.f or; the purpose: of stopping the engine, it is tobeunderstood that other applications to a. battery charging. systemcouldbe; made, hr sulting in modifications of thcfunctionsaof thebattery charging elements, other than the stopping of the engine.

While the form of mechanism herein shown and described constitutes apreferred embodimentof one form of the invention it is to be understoodthat other forms might be adopted and various changes and alterationsmade in the shape, size, and proportion of the elements therein Withoutdeparting from the spirit and scope of the invention.

What is claimed is as follows.

1. In a battery charging system, the combination with an engine drivengenerator and a storage battery to be charged thereby; a chargingcircuit connecting the battery and generator; means dependent on thevoltage of the charging circuit for stopping the engine; and meansdependent on the condition of the electrolyte for rendering the firstnamed means inoperative.

2. In a battery charging system, the combination with an engine drivengenerator and a storage battery to be charged thereby; a chargingcircuit connecting the battery and generator; an ignition system for theengine; means dependent on the voltage of the charging circuit forrendering the ignition circuit inoperative; and means depend cut on thecondition of the electrolyte of the battery for rendering the firstnamed means inoperative.

3. In a battery charging system, the combination with an engine drivengenerator and a storage battery to be charged thereby; a chargingcircuit connecting the battery and generator; an ignition circuitincluding a switch; a cutout relay connected across the charging circuitto open the ignition switch; and means dependent upon the condition ofthe electrolyte to render the relay inoperative.

4. In a battery charging system, the combination with an engine drivengenerator and a storage battery to be charged thereby; of a chargingcircuit connecting the battery and enerator; an ignition circuitincluding a switch; a cutout relay including an electromagnet andarmature, said magnet winding being connected across the chargingcircuit; and a displacement member in the electro lyte cooperating withthe armature of the relay to prevent the action of the relay undercertain battery conditions.

5. In a battery charging system, the combination with an engine drivengenerator and a storage battery to be charged thereby; of a chargingcircuit connecting the battery and generator; a voltage controlleddevice in the charging circuit to cause stopping of the engine; and adisplacement member in the electrolyte to prevent the operation of saidvoltage controlled device.

6. In an electrolyte-controlled circuit breaker, a combination withswitch members; of an armature for effecting the opening or closing ofthe switch members; an electromagnet for attracting the armature; and adisplacement member in the electrolyte of the storage battery, connectedwith the armature whereby the operation of the said magnet is affectedwhen the electrolyte is in a certain condition.

7. In an electrolyte-controlled circuit breaker, a combination withswitch members; of an armature for effecting the open ing or closing ofthe switch members; an electro-magnet for attracting the armature; and adisplacement member in the electrolyte of the storage battery. connectedwith the armature whereby the operation of the said magnet is affectedwhen the electrolyte is in a certain condition, said displacement memberhaving a tapered upper end.

8. In an electrolyte-controlled circuit breaker, the combination with astorage battery containing electrolyte; of switch members; adisplacement member suspended in the electrolyte of the storage battery,and operatively associated with the switch members, said displacementmember having a tapered upper end located near normal level of theelectrolyte, whereby the increase in specific gravity of the electrolyteand the fall of its surface level due to evaporation is compensated forby the decrease in the quantity of electrolyte displaced.

9. In a battery charging system, the combination with a current sourceand a storage battery adapted to be charged thereby; of a chargingcircuit connecting the current source and the battery; means dependenton the voltage across the battery for interrupting the charging circuit;and means dependent on the. condition of the electrolyte for renderingthe first named means inoperative.

10. In a battery charging system, the combination with an engine drivengenerator and a storage battery to be charged thereby; a chargingcircuit connecting the battery and generator; an ignition circuitincluding a switch; and means for opening the ignition switch, saidmeans comprising a device responsive to the voltage of the battery, anda second device responsive to the condition of the battery electrolyte.

In testimony whereof I afiix my signature.

CHARLES F. KETTERING.

IVitnesses:

J. W. MCDONALD,

InvIN A; GREENWALD.

